(3), where LH = 1-H-2-phenylbenzimidazole, LMe = 1-methyl-2-phenylbenzimidazole, LPh = 1,2-diphenylbenzimidazole, and H 2 dcbpy = 2,2′-bipyridine-4,4′-dicarboxylic acid, has been synthesized and fully characterized by elemental analysis, 1 H and 31 P NMR spectroscopy, mass spectrometry, and single-crystal X-ray analysis. The complexes show strong luminescence in the yellow-orange region in ethanol at room temperature (quantum yield is up to 22 %), and

A novel β‐diketone ligand bearing a thiophene moiety and an anchoring Ph‐COOCH3 unit has been designed, prepared and used in synthesis of cyclometalated benzimidazole‐based iridium(III) complexes for application in dye‐sensitized solar cells (DSSC). The replacement of traditional 4,4'‐dicarboxy‐2,2'‐bipyridine by this aromatic β‐diketone results in excellent tuning the redox potentials and excited state properties of these IrIII complexes, one of which exhibits good efficiency when used as a dye in DSSC. All the complexes demonstrate reversible redox behavior, with oxidation potentials (Ir4+/Ir3+) strongly depending on the electron‐donor/withdrawing nature of the substituents in the cyclometalated ligands. Surprisingly, the latter has just a little effect on their luminescence spectra, in which structured emission bands are observed. Time‐resolved spectroscopic studies in combination with DFT calculations show that the complexes emit light by mixed 3MLCT–3LC excited states predominantly composed of the diketone ligand‐centered triplet state.

Nine pairs of cone and 1,3-alternate calix[4]arenes having distal propargyl or 2-azidoethyl groups at their phenolic oxygens were thoroughly studied at macrocyclization under copper(I) catalysis (CuAAC, copper(I)-catalyzed azide-alkyne cycloaddition). Though...

No abstract

Cyclometalated Ir(iii) complexes with bulky 2-arylphenanthroimidazole ligands possess tunable optical properties and demonstrate unusually high reactivity.

A new type of donor-acceptor cyclopropane reactivity towards alkenes was revealed for 2-arylcyclopropane-1,1-diesters that contain an OH-group in the ortho-position of the aryl substituent. In this case, the initial cyclopropanes participate in formal (4 + 2)-cycloaddition as synthetic equivalents of ortho-quinone methides which are potential intermediates generated under mild conditions in the presence of a Lewis acid.

The nucleophilic ring opening of donor-acceptor cyclopropanes with the cyanate ion is reported for the first time. Cyclopropanes, spiro-activated with oxindole fragments as acceptors, are shown to undergo transformations into biologically relevant spiro[pyrrolidone-3,3'-oxindoles] while being treated with potassium cyanate under microwave assistance.

A series of cyclometalated Ru(II) complexes with 2-arylbenzimidazoles antenna ligands bearing electron-donor/withdrawing substituents and anchoring 4,4′-dimethoxycarbonyl-2,2′-bipyridine have been prepared and their structure, optical and electrochemical properties have been studied. The...